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Subject: Re: [RFC 10/10] x86/enter: Use IBRS on syscall and interrupts
To:     Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>,
        KarimAllah Ahmed <karahmed@amazon.de>
References: <1516476182-5153-1-git-send-email-karahmed@amazon.de>
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 <20180121135029.GM10086@char.us.oracle.com>
Cc:     linux-kernel@vger.kernel.org, Andi Kleen <ak@linux.intel.com>,
        Andrea Arcangeli <aarcange@redhat.com>,
        Andy Lutomirski <luto@kernel.org>,
        Arjan van de Ven <arjan@linux.intel.com>,
        Ashok Raj <ashok.raj@intel.com>,
        Asit Mallick <asit.k.mallick@intel.com>,
        Borislav Petkov <bp@suse.de>,
        Dan Williams <dan.j.williams@intel.com>,
        David Woodhouse <dwmw@amazon.co.uk>,
        Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        "H . Peter Anvin" <hpa@zytor.com>, Ingo Molnar <mingo@redhat.com>,
        Janakarajan Natarajan <Janakarajan.Natarajan@amd.com>,
        Joerg Roedel <joro@8bytes.org>,
        Jun Nakajima <jun.nakajima@intel.com>,
        Laura Abbott <labbott@redhat.com>,
        Linus Torvalds <torvalds@linux-foundation.org>,
        Masami Hiramatsu <mhiramat@kernel.org>,
        Paolo Bonzini <pbonzini@redhat.com>,
        Peter Zijlstra <peterz@infradead.org>,
        =?UTF-8?B?UmFkaW0gS3LEjW3DocWZ?= <rkrcmar@redhat.com>,
        Thomas Gleixner <tglx@linutronix.de>,
        Tim Chen <tim.c.chen@linux.intel.com>,
        Tom Lendacky <thomas.lendacky@amd.com>, kvm@vger.kernel.org,
        x86@kernel.org, Arjan Van De Ven <arjan.van.de.ven@intel.com>
From:   Dave Hansen <dave.hansen@intel.com>
Message-ID: <83e4ab96-d511-2154-960d-06d8f4506b86@intel.com>
Date:   Sun, 21 Jan 2018 09:22:51 -0800
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On 01/21/2018 05:50 AM, Konrad Rzeszutek Wilk wrote:
> On Sat, Jan 20, 2018 at 08:23:01PM +0100, KarimAllah Ahmed wrote:
>> From: Tim Chen <tim.c.chen@linux.intel.com>
>>
>> Stop Indirect Branch Speculation on every user space to kernel space
>> transition and reenable it when returning to user space./
> 
> How about interrupts?

This code covers all kernel entry/exit paths, including interrupts.
Despite its name, "error_entry" is used by the interrupt path.

> That is should .macro interrupt have the same treatment?

It already does.